Shower area adhesive thickness.

[berlumberley]

Thought I'd get my second post in as well as I want to get started.
I'm tiling 20 x 25 plain white ceramics round bath/shower onto establishes plaster on brick. How do I get the "flat bed" adhesive I need in the shower area please and what thickness adhesive should I be using generally? I've read that I might need a flat bed trowel but don't know what one is. Basically, if I pop to DIY shop this morning, can anyone advise what notched trowel should I be asking for for shower area and for rest of room? The tiles are 5mm thick. Again I'm having last minute jitters as I was about to go ahead using a plastic notched trowel my dad gave me but reading this forum has made me step back and think a bit more about what i'm doing. A lot more to this than I thought initially!! I see now why the tiler who quoted us initially charges what he does!
Many thanks.

 

[faithhealer]

Have a look at this page
http://www.buybrandtools.com/acatalog/Rubi-Trowels.html
I use a 6mm notched trowel for walls, prime with acrylic primer first and cover the wall with adhesive, no gaps or shallow adhesive.

good luck again

 

[berlumberley]

Thanks Faithhealer. Fast response. I presume I need a round notched rather than square? Also, there are a few chunks of plaster skim missing in a couple of places (about hand size). Should I go up to 8mm to be sure the dips are covered? I'm using bal ready mix.

 

[sWe]

You need to match the trowel notch size to the size of the tiles, the type of edhesive, and the eveness of the substrate. 4-6mm square notched for most wall tiles will do fine, and 6-10 will do just fine for most floor tiles. Round notch and u-notch are mostly only useful when using really large tiles.

Edit: Don't use a flat bed trowel. It has it's uses, but you're guarantied to get better coverage of the adhesive with a notched trowel. Notched trowel also produce the exact same layer thickness all the time. A flat bed trowel doesn't, and you'll increase the likelyhood of uneveness in the finished result by using one.

 

[berlumberley]

Thanks. I was only wondering about round notched for 100% coverage (flat bed?) round shower area. I've been reading that no gaps should exist behind tiles in wet areas and didn't know if square notch would do this or not.

 

[sWe]

Square notch will do it just fine if the consistency of the adhesive is good, which is normally the case. When you press the tile into the notched adhesive, any uneaveness in the tile are filled much more efficiently than if you had a solid bed.
Using a flat/solid bed trowel is a different technique alltogether, which has it's uses. When you set mosaics for example, a solid flat bed might be apropriate. Other than that... Skimming... Smoothing SLC... And so on.

 

[berlumberley]

Thanks all.